To become substantially more complicated, especially when this was unforeseen. Colloquial expression, primarily used in (British) English. Origin: by analogy to human biological development in the womb.
Don't pay an arm and a leg for your internet service, switch to -* insert company name here *- today.
By Izabel
An Arm And A Leg
Figuratively, what one would have to sell or otherwise place as collateral in order to afford something of great expense.
Comes from the fact that, when buying things of great expense, it actually feels as if you are having to offer said appendages as collateral for said item you are purchasing.
A metaphor for the concept of equivalent exchange meaning 'at great personal cost', in reference to something gained.
The phrase may have originated from the legend of Edward Elric, an alchemist who attempted to revive his deceased mother and later restored his brother's soul at the physical cost of his left leg and right arm, respectively.
'Hmm, I might go and get a tattoo of one of those Ouroboros things.'
'Be careful, it'll cost you an arm and a leg!'